"I go to a client and look at properties and it tells me False on the GUP and also that it rejected the upgrade package. Both of these are not true because I log into the client and sure enough it is using the GUP correctly."
The Group Update Provider Status in the client properties - designates if the selected machine is a GUP, not if it is using a GUP for update.
As for the rejected package there may be several reasons - client is already on that version, different language package, 32/64bit difference between the installed client and the pushed package.